Respiratory lecture 5-Physiology of the airways

Question 1

What is obstructive pulmonary disease?

Answer 1

When overall volume of the lungs available for gas exchange is unchanged but there is obstruction to the flow of gases along the airways. (NARROWING OF AIRWAYS THAT CONDUCT AIR INTO AND OUT OF LUNGS)

Question 2

What is restrictive pulmonary disease?

Answer 2

The available lung volume for gaseous exchange is reduced, or restricted, but there is no obstruction to airflow. (TLC REDUCED BUT AIRFLOW AND AIRWAY RESISTANCE IS NORMAL)

Question 3

What is the genioglossus?

Answer 3

Bulk of muscle in tounge

Question 4

What is the tensor palati

Answer 4

Muscles running across the back of the soft palette

Question 5

What is an afferent signal?

Answer 5

Nerve impulse going towards the brain bringing information into the brain

Question 6

What is an efferent signal?

Answer 6

Signal going away from brain sending information out to the body

Question 7

What is the snoring noise?

Answer 7

When the soft palette flaps backwards and forwards whenever they breathe in

Question 8

What happens to pharyngeal muscle reflex when you go to sleep?

Answer 8

Your brain relaxes and is slower which slows the reflex down (less powerful and effective). Pharynx doesn’t act quickly enough and you start to snore.

Question 9

How do you detect sleep apnoea?

Answer 9

When tidal volume slowly decreases and stops and starts again

Question 10

What are the clinical features of sleep apnoea?

Answer 10

snoring, daytime somnolence and associated with obesity and hypertension.

Question 11

Why is obesity associated with more active airway reflexes?

Answer 11

Fat around pharynx narrows the airway which means you have to have extra airway muscle activity to overcome the fact your airway is narrowed by obesity.

Question 12

What is CPAP?

Answer 12

Machine that applies positive pressure to the nose which stops pharynx from collapsing at the back as it is kept open by the pressure

Question 13

what is required to keep airway patent?

Answer 13

continuous muscle activity

Question 14

how are muscles controlled in the airway?

Answer 14

via a reflex arc (pharyngeal reflex arc)

Question 15

what happens when you slow reflex down?

Answer 15

Airway control worsens and

Question 16

What slows reflex down?

Answer 16

Sleep and sedative drugs

Question 17

What is epithelium?

Answer 17

lining of body cavity

Question 18

What is airway epithelium?

Answer 18

epithelial cells with cilia on top

Question 19

what happens to epithelial cells as you go down airway?

Answer 19

cells get smaller and thinner

Question 20

What type of epithelial cells do you have in nose and pharynx?

Answer 20

Pseudostratified (nuclei at different levels)

Question 21

What type of epithelial cells do you have in trachea and bronchi?

Answer 21

columnar

Question 22

What type of epithelial cells do you have in bronchioles?

Answer 22

cuboidal

Question 23

why can’t you have cilia in alveoli?

Answer 23

make them too thick for gas exchange

Question 24

What cell type secreted fluid in airway epithelial cells?

Answer 24

goblet cells

Question 25

what makes up sticky part of airway fluid?

Answer 25

Mucin

Question 26

What causes more mucin to be released than normal?

Answer 26

Airway irritation, tobacco smoke, infection

Question 27

What makes smokers lungs different?

Answer 27

They have more goblet cells and therefore more mucin

Question 28

Why do smokers have more goblet cells?

Answer 28

Goblet cells are permanently stimulated

Question 29

What are the two layers of airway fluid?

Answer 29

1. Mucous layer (gel layer) | 2. Periciliary layer (Salt layer)

Question 30

Consistency of mucous layer?

Answer 30

sticky

Question 31

Consistency of periciliary layer?

Answer 31

watery

Question 32

what is cilia inhibited by?

Answer 32

tobacco smoke, inhale anaesthetics, air pollution and infection

Question 33

what does cigarette smoke do to cilia?

Answer 33

paralyze them due to cyanide in it which stops cilia working properly

Question 34

What are the functions of airway lining fluid?

Answer 34

Humidification and airway defence

Question 35

What is humidification

Answer 35

when water evaporates from airway lining and is added to gas

Question 36

why does nose breathing achieve better humidification?

Answer 36

Air has got further to go

Question 37

how does rate of breathing affect humidification?

Answer 37

Air takes further and further down the airway before its fully humidified

Question 38

What happens when you breathe out?

Answer 38

The warm air coming back from lungs heats up epithelia and put water back into airway lining fluid (water condenses)

Question 39

Why do we have the heat and moisture exchange cycle?

Answer 39

we would loose too much water

Question 40

What do epithelial cells control?

Answer 40

The depth of the airway lining fluid

Question 41

Why is depth of lining fluid important?

Answer 41

Cilia can only work if the fluid depth is correct. if it gets too deep the cilia can't reach mucus.

Question 42

How do epithelial cells change the fluid depth?

Answer 42

Change activity of chloride channel. Secrete chloride into water and sodium follows the chloride down the electrochemical gradient so salt amount is controlled. Via osmosis water will follow it.

Question 43

how do epithelial cells remove 'mucus'?

Answer 43

Move fluid up the lungs (cough)

Question 44

what is the clinical feature of CF?

Answer 44

autosomal recessive inheritance

Question 45

whats wrong in CF?

Answer 45

abnormal CF transmembrane regulator protein.

Question 46

What happens as a result of CF?

Answer 46

Progressive lung infection and destruction. All systems with epithelial cells are affected.

Question 47

What are very large particles and where are they deposited?

Answer 47

greater than 8 micrometers (pollen,sawdust) and deposited in nose and pharynx.

Question 48

What mechanism are Very Large and Large particles deposited by ?

Answer 48

Inertial impaction?

Question 49

What are large particles and where are they deposited?

Answer 49

3-8 micrometers and in large airways

Question 50

What are small particles and where are they deposited?

Answer 50

0.5- 3 micrometers and in bronchioles

Question 51

What mechanism are small particles deposited by ?

Answer 51

sedimnetation

Question 52

What are very small particles and where are they deposited?

Answer 52

less than 0.5 micrometers and they are exhaled.

Question 53

how does gravity help?

Answer 53

we rely on sedimentation and gravity to cause smaller particles to fall and get stuck to mucus

Question 54

what determines where particles are deposited?

Answer 54

size

Question 55

where are large particles captured

Answer 55

upper airway mucous

Question 56

where are small particles deposited

Answer 56

alveoli

Question 57

How do lungs defend body?

Answer 57

1. Acts as physical barrier and removal 2. Chemical inactivation (lysozyme, protease enzyme and antimicrobial peptides) 3. Alveolar macrophages

Question 58

Why are CF patients prone to disease

Answer 58

Defence system sensitive to salt levels and if sodium chroride conc is wrong , the defence systems dont work

Question 59

what chemicals do lung cells release?

Answer 59

lysozyme, protease enzyme (anti-protease system) and antimicrobial peptides

Question 60

What are lysozyme?

Answer 60

Protein enzyme that breaks apart cell wall.

Question 61

what are protease enzymes?

Answer 61

enzyme that will attack any protein which stops proteins in viruses or bacteria from being active

Question 62

why are protease enzymes in mucus?

Answer 62

So they aren't in contact with epithelial cells so they don't damage out own cells.

Question 63

what are anti-protease systems?

Answer 63

Defence mechanism against our protease enzymes if they try to damage our own cells.

Question 64

what are antimicrobial peptides?

Answer 64

Naturally occurring antibiotics e.g.human B defensin which are small peptides that the lung releases, they are non specific and they will inhibit the growth of any bacteria.

Question 65

what are alveolar macrophages?

Answer 65

final layer of defence which clean up around alveoli

Question 66

What is the humoral immunological response?

Answer 66

Immunoglobulins

Question 67

What do immunoglobulins do?

Answer 67

inhibit binding of pathogens to epithelial cells, complement activation and recruit other immune cells.

Question 68

what is involved in cell-medicated immunological response?

Answer 68

Epithelial cells and macrophages

Question 69

what happens when you get bacterial infection?

Answer 69

neutrophils will be present at site

Question 70

what happens when you have an allergy?

Answer 70

Eosinophils will be at the site

Question 71

What is 1st layer of defence?

Answer 71

physical removal of inhales pathogens

Question 72

What is 2nd layer of defence?

Answer 72

non-immunological processes destroy pathogens

Question 73

what is 3rd layer of defence?

Answer 73

immune cells are present in the airway